Turned Art Object – #5 Turning, Dying & Gluing in the Oak Insert – Part 2

Now the in-progress blackwood insert needs to have the roughly 1” wide profile turned.  Below in the drawing at the top the red arrow points to the needed profile shown in white so it’s easier to see.  The bottom photo is of the template that will be used to check my turning.  One change from the drawing is rather than have an angular ridge I changed it to a bead.  Process for making the template is the same as the previous.

Mounting the insert on the 4-jaw chuck in the lathe requires a 1 1/8” diameter hole.  This is smaller than the mounting hole on the other side because if I drilled a 2 ½” hole like the other side I would have ended up with a good-sized hole in the center.  This is due to the larger center point in the 2 ½” drill and the relatively thin section between the two holes.  The resulting hole would make it hard to use the live center in the tail stock to stabilize and center the insert.   The photos below show the size difference between the two sets of jaws.

Below in the left photo the hole for the small jaws has been drilled and the right photo shows the blank flipped and mounted on the smaller jaws.  You can see how much difference there is between the mounting holes.

Turning the profile to match the template is next.  First step is to cut a notch to the finished depth of the profile which is marked by the two red arrows shown in the left photo.  Turning the profile consists of working from the inside out cutting away a little at a time then checking it against the template.  The right photo shows the finished profile.  In that photo the red arrow shows the approximate location of the inside face of the insert.  Later on, everything inside of the red arrow will get cut away.

Dying the oak insert black with India Ink is next.  This needs to be done before insert gets glued in so I get a good clean demarcation line between it and the turquoise inlay.  I am pretty sure that I could not dye the oak after it’s installed without getting some on the turquoise.  The ink gets rubbed into the oak and all of its pores using a small cloth.  Even being careful there are some specks that invariably show up once the ink is dry as white spots which is the undyed oak pores.  It’s not a big problem as a small fine brush is used to spot fix them.  The center does not have ink applied since everything from the red arrow inward will be cut away later on.

Turning a mirror image of the cherry body profile on the second side is next but first a mounting hole gets drilled in the finished body face so it can be mounted facing the chuck.  Once lightly mounted the center reference hole is used to square the piece to the lathe’s axis, then the chuck is tightened and the turning can start.

Process for turning the second face is the same as the already completed face although making a mirror matching face can make one want to pull their hair out.  Free hand turning a single face is pretty easy but when you try and match it things become a lot harder which is why I spent so much time turning the first face to the template.  The left photo shows the profile finish turned and the right photo shows an edge on view that shows how the two profiles match.  The mirrored face is actually closer than shown because the camera setup is a little off to the left causing some distortion. 

The rest of the work for this face; adding the turquoise inlay and cutting the recess for the oak insert is almost the same as the first side.  The one exception is that it does not need the 2 ½” diameter mounting hole on this side for reverse mounting.

The oak insert is made the same way as the first one for the other side.  The left photo shows the second insert fitted into the body.  The right photo is a closer look at how the insert ends up with no gap where it meets the turquoise.  The pencil line is a reference for adding a radius to that edge.

The fine fitting of the oak insert requires sharp tools and a very light touch since the difference between being too tight to being too loose is only a couple hundredths of an inch.  An example of the shavings that come off the turning tool when doing this is below.  The top photo gives some scale of the shaving while the bottom photo is a closer view. 

With the back of the insert sized to fit, the blank can be flipped and using the template turned to match the first insert’s profile.  Below the left photo is the first side and the right photo is the second just completed insert.

Once the second insert gets its India Ink black coloring the two inserts can be glued in place.  Here are the pieces in the order they will go into the clamps starting with the plywood disk on the far left followed by the insert, the body the second insert and ending with the plywood disk.  The plywood disks are being used as a buffer between the clamps and the insert so the India Ink won’t get scratched or marred by the clamps. 

Here are the first couple of steps in the glue up.  The photo on the left shows the protective plywood disk down and the insert with a band of glue around the inside face (red arrows).  The right photo has the body set in place with the grain running the same direction as the insert.

The last steps are to apply glue to the second insert, set it into place shown in the left photo then set the plywood disk in place and add the clamps shown in the right photo.

After an overnight cure the clamps, plywood disks and glued body are removed with this result.  Because the glue was applied only to the inner face of the disk and not to its edges, I didn’t have to worry about any glue squeeze out messing up the clean edge between the dyed insert and the turquoise band.

Next Up – Starting the Base & Cutting the Body in Half

Turned Art Object – #4 Turquoise Inlay & Oak Insert Part 1

Inlaying the turquoise into the recess is next.  The inlay consists of an ultraviolet cured resin used as a carrier and bonding agent for the fine turquoise granules.  The photo below shows the resin, turquoise granules, a small UV light for curing and the small spatula used for mixing and application.  Process is to mix the turquoise with the resin at about four parts resin to 1 part turquoise then carefully put it in the recess.  Because the turquoise granules block the penetration of the UV light three layers are needed with each cured separately.

Here is the first layer application in progress.  The small spatula is used to fill the recess about a third of the way full.  Once the recess is partly filled the mix gets cured using UV light.  The process requires a slightly different mindset since it’s not like epoxy, other types of glue or fillers that have a working time where all too frequently one is up against the time limit to get what needs to be done before the material sets.  Not so here because the mix of resin and turquoise does not harden until it’s exposed to UV light.  

In other projects I have used a small battery powered UV flashlight and it works OK but does take some time to get the resin to cure because the light is not all that intense.  Here in the Southwest, we do have a rather large natural UV generator – called the sun.  It’s not that usable in the summer due to the heat and the potential for causing problems with glued up pieces.  However, this time of year the UV radiation is still high but the weather is much cooler.  My process is to sit in a lawn chair with the turned blank in my lap facing the sun while the UV flashlight helps the curing along.  The photo below shows the first layer cured.

Once all the needed layers are in place and cured the body gets put back in the lathe and the turquoise inlay gets turned down flush with the wood.  The whole part is then sanded smooth with the turquoise being sanded up through 800 grit dry paper.  The next step is to start cutting the recess the oak blackwood accent piece will go into.  The top drawing shows the area where the recess will be cut greyed out. The bottom photo between the two arrows shows the initial starting cut.

Here the recess is mostly done with the depth good and the width almost to the finished dimension although to give a margin of error when the center section gets cut out later it does need to be made a bit wider.  I will explain why when I get there.

Drilling the reference hole deeper is next so it is available later on.  The required finished depth from the face is ¾”.  To drill that I first set the tailstock to show a one-inch extension shown in the top photo.  The whole tail stock is then moved until the tip of the drill bit is at the edge of the ruler which is tight against the face of the body. 

Drilling the hole to the proper depth is a simple matter of turning the hand crank on the tailstock until the gauge reads 1 ¾” as shown in the top photo.  The bottom photo has the completed hole drilled ready for the 2 ½” hole to be drilled down so it’s about 1/16” deeper than the bottom of the recess.  

With the center hole drilled to depth the material between it and the recess is removed and cut a little bit deeper leaving the bottom of the recess just a tiny bit higher.  The bottom of the recess marked with the red arrow is then very carefully flattened.  In the photo you can see that there is no light shining between the ruler and the bottom of the recess meaning the bottom is flat and in a single plane.  Moving toward the center there is light between the ruler (at the 2” mark) and those surfaces meaning that there is clearance.  This is so when the blackwood piece gets glued in, I only have to worry about the piece lying flat along the outer red arrow marked surface.

With the recess cut to size the first oak blackwood insert can be started.  In the top right the red arrows point toward the two finished blackwood inserts.  They start out as a glued-up blanks.  The top left shows the first one being glued up while the bottom photo shows it being flattened using the thickness sander.

Once the oak blank is flattened a circle slightly larger than the finished insert is cut out on the bandsaw.  For symmetry in the finished piece the disk is centered on the glue joint between the two pieces.  The joint is a little hard to see because both halves are from the same board and adjusted so the grain matches up pretty well.

Once bandsawn a 2 ½” hole is drilled centered on the disk just like I did earlier on the main body blank.  After mounting the disk in the lathe, the face gets aligned so it runs true or as close as I can get it followed by taking a very fine facing cut to bring it truly square.  Turning the outer edge flat and square is next.  Once that’s done a very shallow cut leaving a raised circle is very carefully turned down until it just fits inside the recess cut in the body.  The red arrows point the this.  Note that the edge is at a slight angle.  This along with some trial and error lets me sneak to a perfect fit where the body will fit over the slightly narrower outside edge but the inside is still a little too big.  

With the outside diameter set a tenon needs to be turned to exactly match the depth of the recess in the blank.  I got as close as possible measuring with the dial calipers overshooting the tenon length by a few thousands of an inch leaving a tiny gap between the lip and the turquoise.  From there the tenon is carefully shortened until the lip on the piece just touches the turquoise band. Accomplishing this took quite a bit of trial and error because I couldn’t see how the tenon was to fitting to the bottom of the recess.  

Here is what the oak blackwood piece set into the body looks like.  It’s not black yet but it will be when dyed with India Ink.  There is still quite a bit of turning and other work before this piece can be installed but it gives an in-progress idea of how it looks.

Next Up – Turning, Dying & Gluing in the Oak Insert Profile – Part 2

Turned Art Object – #3 Fixing Reference Hole, Body Face Template & Turning 1st Body Face

Since the existing reference point is off just a little, I need to relocate it.  If it was way off, I could just drill a new hole but it’s so close if I try and drill it at the correct location the drill bit would just bend to follow the existing hole.  My way around that is to plug the existing hole then drill a new hole in the right place.  This starts by drill in a much larger hole than needed for the plug with a short stiff Fostner bit followed by drilling a medium size pilot larger than the center point of the brad point drill used for the final hole the plug will be glued into.  What’s shown in the left photo is the final plug hole drilled using the brad point drill.  This drill is used because with the medium size pilot hole the spurs at the edge of the bit guide it rather than the center point which now just spins in midair.  The right photo shows the plug cutter bit being used to make the plug.  

The top left photo has the plug just set into place.  The tail stock with a flat center is then used to press the plug the rest of the way in shown in the top right photo.  The bottom left photo is after the Fostner bit has drilled the face of the plug down flush with the bottom of the first drilled large hole and the bottom right photo is after the new reference hold has been drilled.  Not shown was using the point of the live center in the tail stock to make a dimple for the new reference hole.

These two photos show how the live center will fit into the new reference hole which is 1/64” smaller than the pointed tip (red arrow) for a tight fit.

With a new reference hole drilled the 2 ½” mounting recess for the 4-jaw chuck is drilled finishing this bit of repair work. 

Before starting to turn the body of the piece I printed out a full scale section of about ¾ of it then glued that to a thin piece of plywood.  That’s shown in the top photo.  Using the bandsaw the half pattern gets cut out.

Cleaning up the bandsawn edge is next which as you can see in the top photo is pretty rough.  This starts with a large diameter sanding drum shown the bottom photo.  It’s used for most of the piece but as one gets closer to the left end the diameter of the drum is bigger than the arc of the pattern so I have to shift to a smaller drum.

Consecutively smaller drums are used with the last little bit done using a small round file.  The final smoothing and fairing of the pattern is done with sandpaper.  The bottom photo shows the finished pattern edge.

Turning the face curve on the body is next but to help me in getting close to the finished profile some dimensions get added to the template.  They are ½” apart and give me the depth of the material that needs to be removed.  To use I lay out lines ½” apart on the face of the blank then cut a slot just a little short of the listed dimension.  The top drawing below shows the distances and the bottom has them cut into the blank.

When the blank gets turned down to the bottom of the reference slots the form starts to take shape as shown in the two photos below.  The shape shown is really just roughed out but most of the material is now removed and from here on it’s working with the template to get the profile right.

Once the profile gets 99% done the final shaping is made to the curved surface so it flows smoothly without any high or low spots using sandpaper.  The first of the two sides is now done and ready for the turquoise inlay to be added. 

Before I could start on the inlay, I got an email from a friend who asked if I was interested in some extra wood in the form of four 3-inch square maple bed rails that are about 100 years old he no longer had any use for.  Since it’s hard for me to turn down free material like that a visit to his shop got scheduled.  When I got there, he had some other planks most of which are rough sawn and a couple of inches or better thick all for the taking.  They include the maple bed rails plus a good amount of walnut, some chinkapin, big leaf maple, white oak and some very old rosewood planks.  They all did fit in the car with the seats down but it was a pretty full load and is really appreciated. 

Getting back to the project adding the turquoise inlay is next.  This starts by cutting a recess using a narrow parting tool.  The recess is a little over 1/16” deep and a little over ¼” wide with the red arrows indicating its edges.  As discussed before since I knew that the body turning was going to be taken in and out of the lathe and had to be in almost prefect registration for the various parts to fit together.  With the profile turned and the inlay recess added it now seemed like as good a time as any to see how well the remounting reference hole worked.  Fortunately, the planning and relocated reference hole worked as planned when remounted in the lathe everything was centered and the blank ran true.

Next Up – #4 Turquoise Inlay & Oak Insert Part 1

Turned Art Object – #2 Materials, Making the Blank & a Problem

Pulling the material out of my stock is next.  In the photo below the two short pieces on the left are oak, the two on the top right are 1 7/8” square leopardwood and the large piece on the right along with the long piece at the bottom is 1 7/8” thick cherry.

After measuring the long cherry piece, I thought that there was just enough to get the body out of it, if everything worked just perfectly.  The constraint is not the thickness but the width of the individual pieces.  The final design diameter is 12” and I want a 12 ¼” diameter blank to give me a 1/8” buffer around the edge, not a lot but enough.  To give me the maximum usable material a thin kerf saw blade is used.  The left photo below has the thin-kerf blade on the left and a regular kerf blade on the right.  Now it’s not a lot thinner but there are seven joints in the blank so every little bit helps.  To set the fence for the cut the minimum piece width is marked on the end of the board and the fence set so the body of the blade is centered between those two lines as shown in the right photo.  It’s important to use the body of the blade and not one of the teeth since the teeth have a left and right set to them.  With a careful centering of the blade body, I can get a matched set of pieces with thickness to a few thousands of an inch of each other.

The long boards now get cut to length using a stop block and the chop saw except for the outer two pieces because they don’t have to be as long as the others.  I did not cut them right away because I think there is almost enough to get them from the remainder of one of the long boards.  If they get cut from the last two blanks I would end up a couple of short waste pieces.  This will make more sense in the next photo.  To keep them in sequence the end of each board is lettered and numbered.

To see if the end pieces can be cut from a single piece the remainder of the parts get clamped together and a circle is drawn on them the size required for the blank.  I can then measure the length required for the outer pieces which lets me know if one piece is long enough for both or if I will need to cut one from each of the remaining blanks.  As it worked out one board cut in half was enough with just a little to spare.  The photo below shows the finished clamped dry fit assembly with the short outer pieces.

Gluing the pieces together is next.  The top photo shows the pieces turned ¼ so the glue face is up.  The short piece near the bottom of the photo is the end piece and won’t need glue since there are eight pieces and seven joints.  In the bottom photo the glue has been applied using a fingered rubber glue spreader set in the blue holder at the top.  You can see where the glue stops short on the last clamped piece because that’s where the short end piece goes.  Here I used a waterproof glue not because it’s waterproof but because the dried color is closer to aged cherry.

Once the glue cures the blank gets run through the thickness sander to flatten it along with cleaning up the top and bottom surfaces so it’s ready to be rough cut to size. 

Cutting a circle a ¼” larger than needed on the band saw is next.  Since it had been some time since I checked the squareness of the table to the blade, I took just a minute to do that using my small steel square.  The top left photo shows everything was good and square and the top right one is ready to start cutting.  The bottom photo has the blank cut round.

Drilling a small hole through the center of the blank using the drill press is next.  This will be used for registration when the blank gets reversed during turning.  With a small hole dead center, I can use the live center in the tail stock to get the blank’s axis dead on with the lathe’s axis and provide some extra support when turning.

Next is to drill a 2 ½” diameter recess in one face where the four jaw expanding chuck will go to hold the blank in place while turning.  The outer pencil line is the outside edge where the inlay will go and the inner line is the where the through hole will eventually go. 

With the mounting hole drilled mounting the blank in the lathe for a squareness test is next.  Below you can see a drive center on the left and the live center on the right both inserted into the small through reference hole.  In theory because the reference hole is square to the blank and used to align the blank to the lathe’s central axis it should spin smoothly with no wobble.  Good plan that didn’t work as well as I thought because when spun the blank wobbled about 3/32” side to side and that’s too much.  

To rectify getting the blank square with the lathe’s axis is first.  That can be done a couple of ways one of which is shown below using a dial indicator.  It’s attached to the lathe’s bed via a magnetic base then the contact point is set against the face of the blank shown below.  The blank is spun and the amount of wobble is read on the dial.  Squaring is an iterative process of finding the high and low points then tapping the high point toward the low side half the total wobble then repeating until the high/low difference is acceptable.  After the blank was square, I checked to see how far the reference hole was from the point of the live center and it was just a tiny bit off.  Some calculations showed that to get the 3/16” total wobble the reference hole only needed to be out of square by .4 degrees or .015”.  However, I still need an accurate reference point so when taking the blank in and out it can be set up square.

Next Up – Fixing Reference Hole, Body Face Template & Turning 1st Body Face